A drive unit for a hybrid vehicle is known from DE 10 2006 059 591 A1, whereas the drive unit comprises a drive assembly with an internal combustion engine and an electric motor and a transmission shifting between the drive assembly and an output. The transmission is designed as a dual-clutch transmission and includes several sub-transmissions. Through a planetary transmission, the electric motor of the drive assembly of the drive unit is coupled to an input shaft of a first sub-transmission and an input shaft of a second sub-transmission shifted in parallel to the first sub-transmission. Through a frictional-locking separating clutch, the internal combustion engine is able to be coupled to the input shaft of the first sub-transmission and, if the separating clutch is locked, is directly coupled to the input shaft of one of the sub-transmissions.
An additional drive unit for a hybrid vehicle is known from DE 10 2010 061 824 A1, whereas the drive unit of DE 10 2010 061 824 A1 is distinguished from the drive unit of DE 10 2006 059 591 A1 by the fact that a positive-locking bypass shift element is also present, which works together with the planetary transmission in such a manner that, with a locked bypass shift element, there is a torque-proof connection between the electric motor, the input shaft of the first sub-transmission and the input shaft of the second sub-transmission, whereas, with an open bypass shift element, this connection between the electric motor and the two input shafts of the two sub-transmissions does not exist.
With the drive units known from the state of the art, if a power shift is to be carried out from an actual gear of one sub-transmission into a target gear of a different sub-transmission, this can lead to a transient shift impact, which is considered to be uncomfortable.
As such, there is a need for a method for operating a drive unit for a hybrid vehicle, with which, for the execution of power shifts, an uncomfortable transient shift impact can be safely and reliably avoided.